Engine and integrated hybrid powertrain

Abstract

Provided is a system having a hybrid powertrain having a piston internal combustion engine, and a motor/generator, and the motor generator being coupleable to a clutch and thereby a gearbox, the engine further being equipped with a valvetrain control system operable to change the engine valve operation between a first mode in which the engine can operate in a conventional internal combustion mode and a second mode in which pumping losses are reduced when the engine is not operating in a conventional internal combustion mode.

What is claimed is: 
     
       1. A hybrid powertrain having a piston internal combustion engine, and a motor generator, and the motor generator being coupleable to a clutch and thereby to a gearbox, the engine further being equipped with a valvetrain control system operable to change an engine valve operation between a first mode in which the engine is arranged to operate in a conventional internal combustion mode and a second mode in which pumping losses are reduced when the engine is not operating in the conventional internal combustion mode,
 wherein the engine is prevented from operating in the second mode when a fault is detected in the valvetrain control system. 
 
     
     
       2. The powertrain as  claimed in 1 , wherein the motor generator is coupled permanently to the engine. 
     
     
       3. The powertrain as claimed in  claim 1 , wherein the valvetrain control system operates to maintain an inlet and exhaust valve open through multiple strokes of the engine. 
     
     
       4. The powertrain as claimed in  claim 1 , wherein the valvetrain control system operates to maintain an inlet valve open through multiple strokes of the engine. 
     
     
       5. The powertrain as claimed in  claim 1 , wherein the valvetrain control system operates to maintain an exhaust valve open through multiple strokes of the engine. 
     
     
       6. The powertrain as claimed in  claim 1 , wherein the valvetrain control system operates to maintain an inlet and exhaust valve closed through multiple strokes of the engine. 
     
     
       7. The powertrain as claimed in  claim 1 , wherein the engine is caused to operate in the second mode when the engine is being commanded to produce no power or torque. 
     
     
       8. The powertrain as claimed in  claim 7 , wherein the change from the first mode to the second mode is delayed by a predetermined time after the engine enters an engine state to produce no power or torque in response to the command to produce no power or torque. 
     
     
       9. The powertrain as claimed in  claim 1 , wherein the engine is caused to operate in the second mode when the engine is being operated in a no-fuelling or lower fuelling state in order to produce no, or minimal power. 
     
     
       10. A method of operating a hybrid powertrain having an internal combustion engine coupled to a motor generator and a valvetrain controller operable to selectively open and close engine valves, the method comprising:
 receiving a command to put the powertrain into a low loss mode, and 
 responsive to the low loss mode command, actuating the engine valves to reduce pumping losses in the engine as it rotates;
 wherein the engine is prevented from operating in the low loss mode when a fault is detected by the valvetrain controller. 
 
 
     
     
       11. The method as claimed in  claim 10 , wherein the motor generator is coupled permanently to the engine. 
     
     
       12. The method as claimed in  claim 10 , wherein the valvetrain controller operates to maintain an inlet and exhaust valve open through multiple strokes of the engine. 
     
     
       13. The method as claimed in  claim 10 , wherein the valvetrain controller operates to maintain an inlet valve open through multiple strokes of the engine. 
     
     
       14. The method as claimed in  claim 10 , wherein the valvetrain controller operates to maintain an exhaust valve open through multiple strokes of the engine. 
     
     
       15. The method as claimed in  claim 10 , wherein the valvetrain controller operates to maintain an inlet and exhaust valve closed through multiple strokes of the engine. 
     
     
       16. The method as claimed in  claim 10 , wherein the engine is caused to operate in the low loss mode when the engine is being commanded to produce no power or torque. 
     
     
       17. The method as claimed in  claim 16 , wherein actuating the engine valves in response to the low loss mode command is delayed by a predetermined time after the engine enters an engine state to produce no power or torque in response to the command to produce no power or torque. 
     
     
       18. The method as claimed in  claim 10 , wherein the engine is caused to operate in the low loss mode when the engine is being operated in a no-fuelling or lower fuelling state in order to produce no, or minimal power. 
     
     
       19. A non-transitory, computer-readable medium, storing instructions that, when executed by a computer operating a hybrid powertrain having an internal combustion engine coupled to a motor generator and a valvetrain controller operable to selectively open and close engine valves, causes the computer to perform the steps of:
 receiving a command to put the powertrain into a low loss mode, and 
 responsive to the low loss mode command, actuating the engine valves to reduce pumping losses in the engine as it rotates;
 wherein the engine is prevented from operating in the low loss mode when a fault is detected by the valvetrain controller.